Sitting surfaces are commonly provided for the public, e.g. in the form of public benches, particularly in areas of high pedestrian traffic and in places where members of the public are likely to be waiting or sitting for long periods of time. For example, public benches are likely to be found outside of airport terminals, in bus shelters or otherwise nearby bus stops and on train station platforms. Likewise in sports stadiums and other arenas, sitting surfaces are provided for fans and players alike.
When the ambient temperature is cold, it can be uncomfortable to sit for any length of time. For one, the mere act of sitting reduces the effort made compared to standing or walking, which over time can reduce the heat generated by the body. Moreover oftentimes public sitting surfaces are made of tough materials such as metals which often have a high thermal conductivity and/or a large thermal mass thus allowing the sitter's body heat to transfer to the bench quickly and/or persistently leading to the sitter feeling cold.
In certain cases attempts have been made to provide sitter comfort by providing an air heater in proximity to public benches located in a transit shelter. FIGS. 1 and 2 illustrate and examples of a set of public benches installed by the transit authority of a major city. In this example, perforated stainless steel benches are installed over electric space heaters all inside a closed transit shelter with closed doors. Such heaters are intended for use in a fairly closed environment to heat the air therein. In the context shown here, these heaters would require an air tight transit shelter to be effective, which is fairly expensive to implement and impractical or impossible in certain locations. Moreover closed shelters provide more for vandals to destroy. Even in a closed shelter, space heaters mainly heat the air, the sitting surface remaining barely warm when the exterior temperature is cold. Air that was warmed by such a system is liable to escape whenever a door is opened, leading to wasted energy and a cold sitting area. Lastly, the heating elements in such installations are on and active constantly during the cold season, even when no users are present, leading to uselessly wasted energy.
Even in certain indoor conditions, a sitting surface can feel cold. This is often true in areas that are not very well heated, or in places where people are likely to sit shortly after coming in from a cold setting (e.g. the exterior, in cold places) while still feeling cold from their previous setting.
Other related technologies include heated car seats. However, heated car seats are not suitable for outdoor use or for public use, not only because of their non-robust, non-weatherproof construction but also because they rely on a manual on/off/dimmer switch which may be unsuitable for such use.
In cold climates, transit shelters located at bus and train stops are commonplace. For reliability and for reducing damage due to vandalism, such shelters have no door. A resistant bench or seats are provided, and the shelter provides protection from the wind. It is common to provide signage in the shelter. It is known to provide heating in such shelters, however, due to the open doorway, efficiency is poor.